<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    html,body{
      margin: 0;
      padding: 0;
    }
    .item{
      width: 100px;
      height: 100px;
      border: 1px solid red;
      /* padding: 10px; */
      /* margin: auto; */
      /* margin-top: 10px;
      margin-bottom: 10px;
      margin-left: auto;
      margin-right: auto; */
      /* padding-top: 10px;
      padding-right: 10px;
      padding-bottom: 10px;
      padding-left: 10px; */
    }
    .div1{
    }
    .inner{
      border: 1px solid blue;
      width: 50px;
      height: 50px;
      margin:10px;
      margin-left: 10px;
    }
   
  </style>
</head>
<body>
  <div class="item div1">
    <div class="inner">
      inner
    </div>
  </div>
  <div class="item div2">div2</div>
  <div class="item div3">div3</div>
  <div class="item div4">div4</div>
</body>
</html>